| With the development of the information industry,the application of high-frequency soft magnetic films in microwave devices is becoming more and more extensive.FeNi thin films are attractive due to its high permeability,low coercivity,and low hysteresis loss.If the film has only magnetic uniaxial anisotropy,since the easy magnetization direction of the film is determined,when the film is applied to micro-magnetic induction magnetic electronic devices,the high-frequency magnetic properties only shows good performance when the microwave magnetic field is perpendicular to the easy axis of the film.This work adopts the deposition method of multilayer film superposition,which can make the easy magnetization direction of the film no longer limited to a specific direction,and realize the in-plane isotropy of the high-frequency soft magnetic film.In addition,their resonance frequency and the magnetic permeability of the film may be improved.This provides a new basis for the use of magnetic thin films in practical work.This paper focus on FeNi film with single-layer,double-layer and multi-layer magnetic films,and studies its highfrequency magnetic properties.The main research contents are as follows:1.Study the magnetic properties of single-layer FeNi films with different thicknesses prepared by oblique sputtering.The dynamic and static magnetic characterizations of FeNi films with different thicknesses were investigated,and obtain single-layer permalloy films with good uniaxial anisotropy and small coercivity.The experimental results show that the anisotropy of FeNi films decreases first and then remains unchanged with the increase of thickness,the easy magnetization direction of all films is unchanged.2.Study the microwave magnetic properties of double-layer FeNi thin films.(1)Explore the effect of competition of different thicknesses on microwave magnetic properties.The experimental results of dynamic and static magnetic characterization show that the easy magnetization direction of the bilayer films can be changed by mutual sputtering.(2)The double-layer FeNi thin film was prepared in the same way using a silicon wafer substrate.The experimental results show that the easy magnetization direction of the thin film does not change with the change of the substrate.Due to the pinning effect caused by the difference of substrate roughness,the coercivity of the silicon substrate is smaller than that of the glass substrate.(3)Explore the influence of the angle of the bilayer film on the easy magnetization angle of the film.The experimental results show that with the increase of the included angle,the easy magnetization direction of the film shows similar trend of change.3.Explore the effect of multi-directional multilayer films and interlayers on the microwave magnetic properties of composite FeNi films.(1)To prepare multilayer FeNi films,the sputtering directions of two adjacent layers of films were set at an angle of 90°.The experimental measurement results show that with the increase of the thickness of the multi-directional multilayer FeNi film,the film changes from uniaxial anisotropy to a quasi-isotropic film.When the film thickness is less than 200 nm,the film shows uniaxial anisotropy but presents quasi-isotropic when the film thickness is larger than 260 nm.(2)When an intermediate layer of Ru was added to the permalloy films with different thicknesses at a double-layer angle of 90°.The experimental results showed that the resonant frequency of the film was increased from the original 1.35 GHz to 2.03 GHz due to the addition of the intermediate layer of Ru.With the addition of Ru in the intermediate layer,the coercive force of the film with the addition of Ru in the intermediate layer is greater than that without the intermediate layer. |
